Door latch mechanism



May 24, 1955 F. KAISER DOOR LATCH MECHANISM 2 Shets-Sheet 1 Filed NOV. 26, 1952 INVENTOR. 1 521% zaer; BY/ M 2' M y 1955 F. KAISER 2,709,100

DOOR LATCH MECHANISM Filed Nov. 26, 1952 2 Sheets-Sheet 2 a; 5 l5 6 4? y, g4 35 im 3725 36 227 W4 23 INVENTOR. [Fed 5117613 United States Patent 6 DOOR LATCH MECHANISM Fred Kaiser, Brooklyn, N. Y.

Application November 26, 1952, Serial No. 322,621

3 Claims. (Cl. 292 -169) This invention relates to improvements in a door latch mechanism; and has reference, more particularly, to a door latch mechanism of the kind which is contained within a tubular casing which is mortised into a door body, and wherein the latch mechanism is operated by a spindle adapted to be turned by interior and exterior door knobs to which said spindle is connected.

Door latch mechanisms of the kind referred to usually comprise a latch-piece, a pull-plate, either directly or indirectly connected with the latch-piece, whereby to retract the latter, and a cam-piece adapted to be rotated by a door knob operated spindle whereby to actuate said pull-plate; the mechanism so constituted being mounted within a casing which is mortised into the body of a door by which the latch-mechanism is served. in prior art latch mechanisms of this type, it has been customary to journal the rotative cam-piece, by which the pull-plate is actuated, by mounting trunnions thereof in bearing openings provided in the side walls of the casing in which the latch mechanism is enclosed. By reason of such fixed position of the cam-piece, both the mounting of the latch mechanism in its mortised relation to a door to be served thereby, and the mounting of the door knobs in position to dispose the spindle operated thereby in precise aligned relation to the cam-piece, required exercise of great care and precision in carrying out the mounting and fitting operations, and consequently involved considerable expenditure of time and labor upon the part of the operator.

Considering the above, it is an object of this invention to provide a novel construction of door latch mechanism wherein the pull-plate actuating cam-piece is not journaled in the casing walls, and thus disposed in a predetermined fixed position, but rather is of hubless formation and so supported as to be capable of limited but free floating movement in a vertical plane, whereby it can readily shift in said plane and thereby adjust itself to aligned relation to a door knob operated spindle to be operatively engaged therethrough, and tolerance is provided even where some angular deviation of the spindle from true perpendicular to the plane of the door occurs, so that precise predetermined relative positioning of the campiece and spindle is not necessary, thus enabling the operator to assembly the latch mechanism, door knobs and spindle with a door to be served thereby with minimum expenditure of time and labor.

Another object of this invention is to provide a novel form and construction of pull-plate and of coupling connection thereof to the latch-piece, including a pull-spring of novel form and arrangement to yieldably hold the pull-plate in normal position, which pull-spring is independent of a latch-piece projecting spring, so that said pull-spring can be of stronger tension than said projecting spring, whereby the latch-piece is easily yieldable when contacting the striker plate of a door frame, while the pull-spring is adapted to effect desirably stiffer action in door knob turning.

A further object of this invention is to provide a novel relation of the tie-means by which the roses of exterior and interior door knobs are joined to the mortised door latch mechanism.

The above and other objects will be understood from a reading of the following detailed description of the in vention in connection with the accompanying drawings, in which:

Fig. l is a plan view of the latch mechanism, door knobs and spindle as operatively assembled in mounted relation to a door, the latter being shown in horizontal cross-section; and Fig. 2 is a vertical longitudinal sectional view, taken on line 22 in Fig. l, but showing the internal structure of the door latch mechanism in elevation, and in normal door latching position.

Fig. 3 is a fragmentary horizontal longitudinal section, taken on line 3-3 in Fig. 2, but showing the internal structure of the door latch mechanism in elevation; Fig. 4 is a view similar to that of Fig. 3, but showing the internal structure of the door latch mechanism (excepting the campiece) in central longitudinal section; Fig. 5 is a frag mentary vertical cross-section, taken on line 5-5 in Fig. 2; and Fig. 6 is another fragmentary vertical cross-section, taken on line 66 in Fig. 2.

Fig. 7 is a view similar to that of Fig. 2, but showing the door latch mechanism as actuated to retract the latch nosing whereby to release the door from its normal latched condition.

Similar characters of reference are employed in the above described views, to indicate corresponding parts.

Referring to the drawings, the reference character 10 indicates a door to which the latch mechanism of this invention is applied. Mounted in. a mortised opening, extending into the door body ltd from its free edge, is a casing in which the latch mechanism is housed. This casing is longitudinally divided into two half sections 11 and 12, respectively having respective laterally projecting enlargements l3 and 1 along the lengths thereof and intermediate their top and bottom edge walls. The outer ends of the casing sections are suitably attached to and embraced by a perpendicular end plate 15 adapted to be countersunk in the door body edge, and secured thereto, together with an external face plate 16, by screws 17, thus affixing the casing in its mortised assembled relation to the door body.

Disposed in the rearward end portion of the casing section 11 is a frame plate in, the same having a free end portion 19 which projects exteriorly from the rearward extremity of the casing. Said free end portion 19 is indented by an opening Ztl, the purpose of which will be later herein explained. Intermediate its ends, the frame plate 18 is provided with a seating section 21 which is offset from the plane thereof so as to lie within the interior of the enlargement 13 of said casing section 11, with its inner face flush with the plane of the side wall portions of said casing section. The rearward end portions of the casing sections 11 and 12, together with the frame plate 18, are secured in assembled relation by a rivet 22, or similar fastening means, which extends transversely therethrough.

A hubless fiat sided rotative cam-piece 23 is embraced by the frame plate 1% so as to overlie the seating section 21. thereof, whereby to be supported by the latter subject to limited free floating movement relative thereto in the vertical plane of said seating section. Said cam-piece is provided with oppositely and substantially radially extending cam arms 24.

Supported in the forward end portion of the casing section 11 is a longitudinally slidable latch-plate 25, to the forward end of which is suitably afiixed a chamfered latch-nosing 26. Said latch-nosing 26 extends outwardly through the casing end plate 15 and face plate 16, so as to normally project outwardly from the free edge of the door body 10. The latch-plate is provided with a rectangular longitudinal internal opening 27.

Longitudinally slidable in the mid-portion of the interior of casing section 12 is a pull-plate 28, so disposed that its forward end portion overlies the rearward end portion of the latch-plate 25, while its rearward end portion overlies the forward end portion of the frame plate 18. Extending from the rearward end of the pullplate 28 are laterally spaced legs 29 which overlie the cam-piece 23 which is floatingly supported by the seating section 21 of the frame plate 18. The outer end portions of said legs 29 are provided with stop projections 30 adapted to extend laterally outward from the outer side edges of said legs. The top and bottom edge walls of the casing sections 11 and 12 are cut away to provide openings 31 of suitable length in which said step projections 30 are disposed to move back and forth therein. The respective ends of said openings 31 are engageable by said stop projections 30, whereby to limit the forward and rearward longitudinal movements of the pull-plate when the same is actuated. The extremities of said legs 29 of the pull-plate are provided with offset angular retractor lugs 32 disposed to straddle the cam-piece 23 so as to be respectively positioned behind the respective cam arms 24 of the latter, subject to operative engagement thereby. The forward end of the pull-plate 28 is provided with an ofiset angular coupler member 33, which extends through the opening 27 of the latch-plate 25, whereby to operatively couple said latch-plate to the pull-plate. shape, with its shank engaged in said opening 27 of the latch-plate 25. The body of the pull-plate 23 is provided with a central longitudinal slot 34 of suitable length. Struck outwardly from the body of the pullplate 28, adjacent the sides of said slot 34 are spring attachment hook elements 35 which project into the interior of the enlargement 14 of easing section 12. Struck from the face wall of said enlargement 14 of casing section 12 is a central spring anchoring post 36, which is disposed in forwardly spaced relation to the spring attachment hook elements 35 of the pull-plate. The pull-plate 28 is yieldably maintained in forwardly moved normal initial position by a helical pull-spring 37. This pull-spring is doubled upon itself into U-shape, with the bight thereof engaged around and supported by the anchoring post 36, thus providing laterally spaced, rearwardly extending end portions which are respectively attached to the respective hook elements 35 of the pull-plate, whereby to straddle the slot 34 of said pull-plate.

A compression spring 38 is mounted within the opening 27 of latch-plate 25 between the latch-nosing 26 and the coupler member end of the pull-plate 28, whereby the latch-plate and latch-nosing is yieldably urged forwardly to normal latch-nosing projecting position relative to the free edge of the door body 10. This compression spring is preferably of light tensional thrust as compared with a strong tensional pull exerted by the pull-spring 37 upon the pull-plate 28 and parts cooperative therewith. By reason of this, the latch-plate and latch-nosing is easily yieldable when contacting the striker plate of a door frame, while the pull-spring 37 may be made to provide stronger resistance, whereby to effect desirably stiffer action in door knob turning operative to actuate the latch mechanism for latch-nosing retraction and release as will presently be described.

The means for operating the above described door latch mechanism comprises interior door knobs 39 and 40, the shanks of which are respectively journaled in respective rose members 41 and 42, which are respectively mounted on the inner and outer faces of the door body 10. The rose members are fixed in place on the door body by tying means extending therebetween and transversely through the door body and through the latch mechanism which is mortised into the latter. The tying means comprises a pair of spaced internally screw threaded tie members 43 Said coupler member 33 is preferably of T- anism, while the other tie member passes through side openings 45 in the casing sections 11 and 12 and through the slot 34 of the pull-plate 28 of the latch mechanism, thus assembling the door knobs in operative relation to said latch mechanism. Suitably secured to and extending between the door knobs 39 and 40 is a latch mechanism operating spindle 46, which is preferably by polygonal cross-sectional shape. Said spindle is adapted to pass through a correspondingly shaped axial opening 47' with which the cam-piece 23 of the latch mechanism is provided. The side walls of the casing sections 11 and 12 and the seating section 21 of the frame plate 18 are respectively provided with openings 48 and 49, whereby to allow extension of the spindle 46 through the latch mechanism. It will be obvious that, due to the floating support of the cam-piece 23 within the latch mechanism, said cam-piece is free for limited shifting movement in a plane perpendicular to the axis of the spindle 46 in any direction necessary to bring its axial opening 47 into alignment with the spindle 46, whereby to allow operative assembly of the latter with the cam-piece. By reason of this tolerance, the spindle can be quickly and easily assembled with the latch mechanism without necessity for precise predetermined positioning of the door knob structure and the latch mechanism in relation one to the other, and the assembly of these structures in operative relation can be accomplished even when some angular deviation of the spindle from true perpendicular to the plane of the door may occur, since the cam-piece can readily shift to accommodate itself to such condition. It will therefore be understood, since precision fitting of the door knob structure and the latch mechanism to the door body is not necessary, the application of these structures to a door can be more easily carried out with a minimum of time consuming and laborious effort.

In operation, the turning of either door knob will transmit, through the spindle 46, rotative motion to the cam-piece 23, whereby to engage one or the other of the cam arms 24 with a corresponding retractor lug 32 of the pull-plate 28, whereupon a rearward thrust will be exerted upon the pull-plate to retract the same against the tension of the pull-spring 37, and, through its coupled connection with the latch-plate 25, to thereupon retract the latter so as to withdraw and release the latch-nosing 26 from normal door latching projection. Since the pullplate 28 is provided with the elongated slot 34 through which a tie member 43 passes, said slot provides clearance relative to said tie member, so that the latter does not interfere with operative movement of the pull-plate. Similarly, since the pull-spring 37 is of U-shape so as to straddle said tie member 43, neither does the latter in terfere with the operation of said pull-spring.

When, after latch mechanism operating rotation, a door knob is released, the pull-spring 37 returns the pullplate 28 to normal initial position, thereby releasing the latch-plate 25 subject to the pressure of the spring 38, whereby the latch-plate 25 is also returned to normal latch-nosing projecting position.

The coupled linkage of the latch-plate 25 with the pull-plate 28 being operative in connection with the elongated opening 27 of the former, said latch-plate 25 and latch-nosing 26 is free to move rearwardly, independently of the normally positioned pull-plate, against the tension of the latch projecting spring 38 when the door is swung to closed position in its frame. 7

Having now described my invention, I claim: 1. In door latch mechanism, a casing adapted to be mortised into the free marginal edge portion of a door, a latch-plate longitudinally slidable in said casing and provided with a latch-nosing for projecting from the forward end of the casing, compression spring means for yieldably retaining the latch-plate in latch-nosing projecting position, a longitudinally slidable pull-plate, pullspring means to yieldably retain said pull-plate in forwardly moved normal position, means for transmitting retractive movement of the pull-plate to the latch-plate, a hubless flat-sided cam-piece, a frame plate afiixed with in the casing, said frame plate having a laterally offset portion parallel to the plane of said cam-piece to provide a seat upon which said earn-piece is slidably supported for floating movement in all directions radial thereto in the vertical plane of said seat, whereby said cam-piece can shift for alignment with and engagement by a rotative door knob spindle when the latter is inserted therethrough, and said pull-plate having means engageable by said cam-piece for retracting the former upon rotative operation of the latter.

2. In a door latch mechanism, a casing adapted to be mortised into the free marginal edge portion of a door, a latch-plate longitudinally slidable in said casing and provided with a latch-nosing for projection from the forward end of the casing, compression spring means for yieldably retaining the latch-plate in latchnosing projecting position, a longitudinally slidable pull-plate, pullspring means to yieldably retain said pull-plate in forwardly moved normal position, means for coupling the latch-plate to the pull-plate comprising an angular coupler member at the forward end of the pull-plate, said latch plate having a longitudinal internal opening through which said coupler member extends in normal engagement with the rearward end thereof, said compression spring for yieldably retaining the latch-plate in latchnosing projecting position being lodged in said latch-plate opening to engage between said coupler member and the forward end of the latter, a hubless flat sided cam-piece, means afiixed within the casing to supportingly seat said cam-piece for floating movement in all directions radial thereto in a vertical plane, whereby it can shift for alignment with and engagement by a rotative door knob spindle when the latter is inserted therethrough, and said pull-plate having means engageable by said cam-piece for retracting the former upon rotative operation of the latter.

3. In a door latch mechanism according to claim 2, wherein the pull-spring for the pull-plate comprises a helically coiled spring doubled upon itself into U-shape with its ends secured to said pull-plate in straddling relation to said slot thereof, and the casing of the latch mechanism having a fixed anchor post to which the bight of said spring is attached.

References Cited in the file of this patent UNITED STATES PATENTS 1,895,894 Moore Jan. 31, 1933 2,238,314 Falk Apr. 15, 1941 2,634,151 Russell et al. Apr. 7, 1953 2,644,704 Hagstrom July 7, 1953 

